Grape seed extract (GSE) was encapsulated in biocompatible poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) using the solution enhanced dispersion by supercritical fluids (SEDS) technique. In order to help selecting the appropriate operating conditions for the encapsulation mechanism, the fluid phase behavior of pseudo-ternary carbon dioxide (CO2) + dichloromethane (DCM)+GSE systems was studied employing a static synthetic method. The investigated SEDS operating parameters were in the following range: pressure (8-12 MPa), temperature (308-318K), GSE to PHBV mass ratio (1:1-1:3), with concentrations of organic solution formed by GSE (6.67-20.00 kg m(-3)) in DCM, and fixed PHBV 20.00 kg m(-3) in DCM. The organic solution flow rate was fixed at 1.67 x 10(-8) m(3) s(-1) and the antisolvent flow rate at 3.33 x 10(-7) m(3) s(-1). The effect of operating parameters on particle size, particle morphology and encapsulation efficiency was checked. The best result was obtained at 8 MPa, 308K, GSE to PHBV mass ratio of 1:1, with concentration of GSE and PHBV, both of 20.00 kg m(-3), leading to spherical particles with the smallest size of similar to 0.70 mu m and encapsulation efficiency of 66.01%. SEM-EDS micrographs showed that, besides spherical particles, agglomerated particles were observed at temperatures higher than 308 K, which might be due to a more favorable extract re-dissolution at higher temperatures.